Renewable fuse



H. GOODWIN.

RENEWABLE FUSE.

APPLICATION FILED JULY 20. 1920.

1 ,405,682, Patented Feb. 7, 1922.

- //7 wen/ or- /7 9// 6000 40/27 UNITED STATES PATENT orrice.

HALL GOODWIN, OF CHICAGO, ILLINOIS.

RENEWABLE FUSE.

To all whom it may concern Be it known that I, HALL GoonWIN, a citizen of the United States, residing at Chicage, in the county of Cook and State of Illinois, have invented new and useful I mprovements in Renewable Fuses, of which the following is a specification.

This invention relates to electric fuses in which the fusible member is so held that it can be removed for renewal when it becomes ruptured.

The invention has for its object to provide a fuse of this kind composed of a minimum number of simple and easily assembled parts which permit ready removal, when necessary, of the fusible element.

The object stated is attained by means of a novel combination and arrangement of parts to be hereinafter described and claimed, and in order that the same may be better understood, reference is had to the accompanying drawing forming a part of this specification.

In the drawing,

Figure 1 is a central vertical section-of the device;

Fig. 2 is a section on the 1, and

Fig. 3 is a detail in perspective.

The fuse is of that type in which the body has the form of a plug which is screwed into a base socket containing the. contacts by which the device is interposed in the electric circuit to be protected.

Referring specifically to the drawing, 5 denotes the body of the plug, the same being formed of porcelain or other non-conducting material. Over the plug 5 is fitted a sleeve 6 of rubber or other suitable non-conducting material. Sleeve 6 does not completely cover the plug 5 so that one-end of the latter is left projecting from the sleeve, and at the opposite end of the plug, the sleeve projects a short distance from the plug and has its projecting end formed with an internal rabbet 7 to seat and hold a glass lens 8, the latter being cemented or otherwise permanently fitted to the sleeve, and forming a transparent closure therefor.

The projecting end of the plug 5 has external spiral corrugations and is fitted with a sleeve 9 of conducting material which is pressed into the corrugations to produce a screw-thread on the plug.

The end of the plug 5 over which the lens 8 seats is formed with a socket 10 across line 2-2 of Fig.

Specification of Letters Patent. Patented Feb, '1 1922, Application filed July 20,

1920. Serial No. 397,758.

which a fusible strip 11 extends. The lens 8 is concave-convex, its concave side facing the socket 10, and the strip 11 extending across thesame. The socket and lens form an air chamber across which the fusible strip extends, and the rupture of the strip takes placein this chamber, the same having sufiicient area to take care of the gases resulting from the fusing of the strip.

In the side of the plug 5 are diametrically opposite longitudinal grooves in which seat conductor strips 12 and 13 one of which is in electrical connection with one end of strip 11 and the other with the other end of the latter. The strips 12 and 13 are flush with the surface of the plug 5.

The strip 12 is made integral with the sleeve 9; or it can be made separate and soldered to the sleeve, or otherwise joined thereto to establish an electrical connection.

The strip 13 is electrically connected to a contact element 14 embedded centrally in the plug 5 and exposed at the end thereof on which the sleeve 9 is fitted, the exposed portion of the element being enlarged to form a head 15, and its inner end having a lateral bend issuing from the side of the plug for electrical connection with the strip 13.

The strips 12 and 13 extend along the sides or the plug 5 as far as the socketed end of-the latter across which the strip 11 extends. The inner ends of the strips 12 and 18 have lateral bends 16 across the end of the plug and for a short distance into the socket 10. The ends of the strip 11 seat on the bends l6, and they are held firmly in contact therewith by the lens 8 when the sleeve 6 is slipped on the plug 5. It will be noted that a few of the corrugations of the plug 5 forming the screw'thread extend into the sleeve 6, and the latter has matching internal threads. is therefore applied to and removed from the plug 5 with a twist or slight turning movement, and when in place on the plug, the strip 11 is securely clamped at its ends between the lens 8 and the bends 16 of the strips 12 and 13 to maintain an electrical connection therewith. When the strip 11 burns out, it can be readily removed. and renewed upon separation of the sleeve 6 the plug'5.

The end of the plug 5 on which the bends 16 seat is grooved transversely to receive said bends, the grooves being deep enough to The sleeve 6 a and also seat the ends of the strips 11 and thus prevent lateral displacement thereof. The

grooves are intersected by a deeper annular groove 17 and coinciding therewith the inner side of the lens 8 has an annular rib 18. When the sleeve 6 is applied to the plug 5, the rib 18 forces the bends 16 and the ends of the strip 11 into the groove'17, whereby said parts are securely clamped in assembled relation. It will be noted that the bends16 are turned in to enter the socket 10, which assists to hold the strips 12 and 13 in place on the plug -5.

To prevent'separation of the plug 5 and the sleeve 6 when the device is being screwed out of the basesocket'containing the electrical connections, a flat spring 19 is secured to the outside of the sleeve 6 at one end, as shown at 2.0, the free end of the spring carrying a latch pin 21 *seating in alined apertures in the plug 5 and the sleeve parts 5- and 6 can be readily separated for renewal of the strip 11, upon prying the pin 21 out of its kee er apertures in said parts, the free end of the sprin 19 being bent laterally so that an'easy nger'hold is obtained. 7 vv I claim:

An electric fuse comprising a plug of insulating material having a-socket in one end, a sleeve of insulating material detachably fitted over the socketed end of the plug and havin a transparent closure over said end, a fusi le element extending across the socketed end of the plug, and conductor members carried by the plug, the ends of the fusible element seating on said conductor members and being clamped thereagainst by the aforesaid sleeve, the plug end having an annular groove and the sleeve having a coinciding rib for forcing the contacting portions of the fusible element and the conductor members into the groove.

In testimony whereof I aflix m'y signature.

. HALL GOGDWIN. 

